As we forge ahead into a new year, we carry with us the lessons of 2012.

There were more reminders of the sad fragility of life, but also more evidence of the power of one voice demanding justice. We saw the evil in mankind and those who bravely risked everything in the name of humanity and freedom.

Anderson Cooper traveled the country and the world seeking the truth and meeting the people whose lives took a dramatic turn this year. He also honored the legacy of icons and heroes who passed away. Among them, we said goodbye to entertainers Dick Clark and Whitney Houston, and remarkable journalists Marie Colvin and Anthony Shadid.

The most extraordinary heroes were those who never expected recognition. Like the nurse who managed to keep a baby safe while the tiny patient was transferred to a different hospital's NICU because of a power failure during Superstorm Sandy. The New Yorker who single-handedly rescued a taxi driver about to drown as the flood waters enveloped his car. The teen who faced gunfire to try to rescue a woman, a stranger to him, shot by a sniper in Syria. And the teacher who acted quickly and sacrificed her own life to save elementary school students in Newtown, Connecticut.

Like Anderson does every year, he made it his mission to hold politicians accountable – and there was a lot of opportunity this campaign season. Former elected officials were on the agenda too, like Gov. Haley Barbour who pardoned convicts before leaving office. With Drew Griffin's deft investigative reporting, we went after charities that misled donors by collecting millions of dollars and not spending it where expected.

The legal cases that caught everyone's attention in 2012 were fascinating and divisive. Dharun Ravi, Jerry Sandusky, and George Zimmerman became household names. In some cases, justice was served and others remain unresolved. We'll continue to monitor the baby Veronica custody battle and the other ongoing legal battles.

If you watched in 2012, we thank you (a lot). If you tweeted or posted your views about AC360's stories and interviews, we read it and want to hear more from you in 2013. You can find us @AndersonCooper@AC360 and on Facebook and Google+.